Subject: WG Review: Network Mobility (nemo)

From: [email-masked]
Date: Mon, 23 Sep 2002 15:46:07 -0400

A new IETF working group has been proposed in the Network Mobility area.  
The IESG has not made any determination as yet.

The following Description was submitted, and is provided for 
informational purposes only:

Network Mobility (nemo)
-----------------------

 Current Status: Proposed Working Group

Description of Working Group:

The NEMO Working Group is concerned with managing the mobility of an
entire network, viewed as a single unit, which changes its point of
attachment to the Internet and thus its reachability in the topology.
The mobile network is moving as a unit, and includes one or more mobile
routers (MRs) which connect it to the global Internet.

A mobile network is assumed to be a leaf network, i.e. it will not
carry transit traffic. However,it could be multihomed, either with a 
single MR that has multiple attachments to the internet, or by using
multiple MRs that attach the Nemo to the Internet.

Initially,the WG will assume that none of the nodes behind the MR will
be aware of the network's mobility, thus the network's movement needs
to be completely transparent to the nodes inside the mobile network.
This assumption will be made to accomodate nodes inside the network
that are not generally aware of mobility.

A basic approach for Nemo is for each Mobile Router to have a Home 
Agent, and use bidirectional tunneling between the MR and HA to
preserve session continuity while the MR moves. The MR will acquire a
Care-of-address from its attachment point much like what is done for
Mobile Nodes using Mobile IP. This approach allows nesting of Nemos,
since each MR will appear to its attachment point as a single node.

The WG will take a stepwise approach by standardizing some basic
support based on the bidirectional tunneling approach, and at the same 
time study the possible approaches and issues with providing more
optimal routing than can be had with (potentially nested) tunneling.
However, the WG is not chartered to actually standardize a solution to
such route optimization for mobile networks at this point in time.

The WG will work on:

- A threat analysis and security solution for the basic problem
  (tunneling between HA and MR)

- A solution to the basic problem for both IPv4 and IPv6.
  The solution will allow all nodes in the mobile network to be
  reachable via permanent IP addresses, as well as maintain ongoing
  sessions as the MR changes its point of attachment within the
  topology. This will be done by maintaining a bidirectional tunnel
  between the MR and its Home Agent. The WG will investigate reusing
  the existing Mobile IPv6 mechanisms for the tunnel management, or
  extend it if deemed necessary.

- An informational document which specifies a detailed problem
  statement for route optization and looks at various approaches to 
  solving this problem. This document will look into the issues and 
  tradeoffs involved in making the network's movement visible to some 
  nodes, by  optionally making them "NEMO aware". The interaction 
  between route optimization and IP routing will also be described in 
  this document. Furthermore, security considerations for the various 
  approaches will also be considered.

The WG will:

- Ensure that solutions will scale and function for the
  different mobile network configurations, without requiring
  changes to Correspondent Nodes in the Internet. All solutions
  will aim at preserving route aggregation within the Internet and
  will satisfy an acceptable level of security (a thorough survey
  of new threats and an analysis of their severity will be conducted)

- Ensure that various mechanisms defined within other IETF WGs
  will be useful for mobile networks. To achieve this, the NEMO WG
  will interact with other WGs when needed, and may place requirements
  on the protocols developed by those WGs.

The NEMO WG will not:

- consider routing issues inside the mobile network. Existing
  routing protocols (including MANET protocols) can be used to
  solve these problems.